1. Field of the Invention
The present invention relates to enhancements in providing support for very large and heavy loads while simultaneously permitting limited movement of such loads in response to applied forces, particularly forces which are exerted in directions which vary. More specifically, this invention is directed to improvements in bearing devices which are suitable for use in a marine environment, and especially to replaceable, slide bearings which are particularly well suited for use in the support of hatch covers. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
While not limited thereto in its utility, the present invention is particularly well suited for use as a bearing on which a hatch cover of a sea-going vessel may be supported. The problems precipitated by the very demanding use environment of a hatch cover bearing for cargo carrying vessels is discussed in the above-referenced co-pending application, the co-pending application being incorporated herein by reference. Co-pending application Ser. No. 010,611, now U.S. Pat. No. 5,330,271 also discloses a novel and successful approach to solving these problems.
As is the case with most pioneer inventions, some of the operating conditions may on occasion prove to be so exceptionally harsh that modifications to the basic invention are required. By way of example, in the case of the bearing device of application Ser. No. 010,611, the self-lubricating pad which actually contacts the hatch cover could, in theory, be rendered ineffective through damage or actually be "lost". In the unlikely event of such catastrophic damage or loss, the bearing device would be reduced to affording the undesirable metal-on-metal contact of the prior art hatch cover support pads. Thus, a means for rendering the bearing device of the co-pending application "fail-safe" would constitute an improvement.
As yet another theoretical problem with the bearing device of the co-pending application, the pillow plate on which the self-lubricating pad is supported is affixed to the sub-base plate by means of peripheral fillet welds. Such fillet welding of the ends and sides of the pillow plate to the sub-base plate may not provide a mechanical connection of sufficient strength to absolutely ensure that separation of components cannot occur under exceptionally high loading.